The focus power of the eye is insufficient so that light focuses behind the retina. Such eyes are said to be long-sighted because the focus of the eye is better for distance than near. In order to see clearly, the focus power of the eye must be increased.
This can be achieved by a plus (positive) power lens. The spectacle prescription for a low degree of hypermetropia might read “+1.50” to indicate that the focus power of the eye needs to be increased by one and a half diopters.
The focus power of the eye can be increased by surgery in one of two ways – by making the cornea steeper or by replacing or augmenting the natural lens of the eye with an artificial lens of greater power.